MANAGING THE IMPACT OF INVASIVE SPECIES ON SCOTTISH RIVERS. Phil Boon Scottish Natural Heritage, Edinburgh, UK

Transcription

1 MANAGING THE IMPACT OF INVASIVE SPECIES ON SCOTTISH RIVERS Phil Boon Scottish Natural Heritage, Edinburgh, UK

2 APPROACH Managing alien species in Scotland under the Water Framework Directive Exclusively related to WFD Not exclusive to rivers many of the principles are the same in other waters Not restricted to Scotland

3

4 EC WATER FRAMEWORK DIRECTIVE Adopted in 2000 Aims (selected) To prevent further deterioration and protect and enhance the status of aquatic ecosystems To promote sustainable water use

5 SPECIFIC OBJECTIVES OF THE WFD To achieve (by 2015) good ecological status, defined as a slight departure from high status reference conditions principally in terms of plants, invertebrates and fish No deterioration To meet Protected Area objectives

6 EC WATER FRAMEWORK DIRECTIVE A complex directive (70pp) Covers all types of surface waters - rivers - lakes - transitional waters (estuaries) - coastal waters Includes groundwater

7 WATER QUALITY

8 HYDROLOGY

9 MORPHOLOGY

10 PRESSURES Nutrient enrichment Acidification Organic pollution Chemical pollutants Abstraction Flow regulation River engineering

11 WFD BIOLOGICAL ELEMENTS Phytoplankton and phytobenthos Invertebrates Fish

12 WFD HYDROMORPHOLOGICAL AND PHYSICO-CHEMICAL ELEMENTS Hydromorphological elements e.g. hydrological regime, substrate conditions Physico-chemical elements e.g. nutrient concentrations, oxygen levels

13 CLASSIFYING ECOLOGICAL STATUS Classification of water bodies 5 classes: - High status (= reference conditions) - Good status - Moderate status - Poor status - Bad status

14 RIVER BASIN PLANNING Integrated catchment management 6-year cycle Aims to address problems through programmes of measures

15 ALIEN SPECIES AND THE WFD TEXT Not specifically mentioned Guidance from European Commission Constitute a pressure Detract from naturalness

16 UK TECHNICAL ADVISORY GROUP (UKTAG) Set up by the UK Government to provide advice on the technical aspects of the WFD Works through a number of subsidiary groups, e.g. Rivers Task Team Alien Species Group

17 ALIEN SPECIES GROUP Led by statutory conservation agencies TAG guidance on river basin characterisation and on risk assessment (2004) Top 10

18

19

20

21

22

23 ALIEN SPECIES CATEGORIES Red (high impact) list Green (low impact) list Grey (unknown impact) list

24 CLASSIFYING ECOLOGICAL STATUS

25 Classification will provide the impetus for management

26 DECIDING ON THE PRINCIPLES Guidance produced by Alien Species Group, modified by UKTAG and out for public consultation

27 CLASSIFICATION PROCEDURE Is there evidence that a listed highimpact alien species is established in the water body? No Is there other evidence that would prevent the water body being classed as high status? No Classify as high status Yes Yes Is there evidence that the alien species is causing more than a slight adverse impact on any biological element? No Is there other evidence that would prevent the water body being classed as good status? No Classify as good status Yes Yes Classify as moderate or worse

28 BEING PAROCHIAL Not a Scottish directive Not a GB directive Not a UK directive An EC directive Other European countries also adopting it

29 A EUROPEAN APPROACH Need to begin to develop a European consensus on these issues Need EC guidance for all Member States ECOSTAT Bordeaux workshop, April 2008

30 ECOLOGICAL STATUS SOME IMPORTANT ISSUES 1. Naturalised aliens 2. Riparian zone species 3. Native species as aliens 4. Climate change

31 1. NATURALISED ALIENS When is an alien not an alien? When it s been here for a long time???? Setting dates: - UK none - Belgium Sweden Italy France 3000BC

32 2. RIPARIAN ZONE SPECIES

33

34 RIPARIAN ZONE SPECIES To what extent do these species exert impacts on aquatic ecosystems? Should they be used for downgrading a water body from being at high or good ecological status?

35 3. NATIVE SPECIES AS ALIENS Some native species can be as damaging as alien species when deliberately moved outside their historic range Translocated native species

36 RUFFE (Gymnocephalus cernuus)

37

38 RUFFE INVASION ruffe No.= exp (0.866*t)

39 LOCH LOMOND: PREDATOR-PREY RELATIONSHIPS Ruffe

40 4. CLIMATE CHANGE Species distributions will change with shifts in climate This will have impacts both on native and non-native species Some non-native species will be at a competitive advantage as they move in to colonize new areas What approach should we take to these species in status classification?

41 INTRACTABLE PROBLEMS? Do we shrug our shoulders and just give up?

42

43

44 ERNE SYSTEM Lower Lough Erne and Upper Lough Erne - area: 144 km 2 - volume: 2.1 x 10 9 m 3 Number of zebra mussels: 2.3 x Biomass: 4152 tonnes Filtering capacity: 16 days to filter entire lake volume

45 NOT THE END OF THE ROAD Maintain active research programme on alien species control Example: new techniques for controlling zebra mussel Press release March 2008 New York State Museum A strain of bacterium Pseudomonas fluorescens toxicity kills zebra mussels Cells can be dead or living; highly specific

46 WFD PROGRAMMES OF MEASURES Preventing future problems risk assessment Long-term management Partnership approach alien species forums Underpinned by monitoring Early action against new invasions

47

48 ALIEN SPECIES FORUMS Project funded by SNH, SEPA, SG Contract to ADAS Aim: to consider how to manage alien species problems under the WFD Parallel project to one in England Alien species forums Two pilot areas Tay AAG, Argyll AAG

49

50

51 MAIN CONCLUSIONS Some species mentioned frequently (e.g. bankside plants, signal crayfish) Concern over lack of data General support for alien species forum approach based on AAGs but focused on catchments Membership to include SNH, SEPA, fisheries boards, LAs, FC, SG Funding?????